Distinguishing true cellulitis from its many imitators is challenging but critical if we are to avoid unnecessary use of antibiotics and delays in treatment. Common imitators of cellulitis are stasis dermatitis, lipodermatosclerosis, contact dermatitis, lymphedema, eosinophilic cellulitis, and papular urticaria. Specific criteria do not exist for the diagnosis of cellulitis, but the alert physician can find clues in the history and physical examination that point toward cellulitis.